1. Field of the Invention
This invention relates to life safety, and in particular to detectors and alarms for the particulate products of combustion. The invention comprises a combination door-chime/smokedetector which may be advantageously located within non-industrial buildings, particularly of the residential type.
Within recent years, many ordinances, codes and standards have been promulgated which now require some form of smoke detection device in one or two family homes, apartments, and in some instances mobile homes. Many additional such codes and standards are pending as of this date and it is contemplated that within a few years the requirement for smoke detection devices suitable for non-industrial applications, such as homes and apartments, will be almost universal.
2. Description of the Prior Art
The prior art is prolific in smoke detection devices which are suitable for installation in non-industrial buildings. These devices in most instances employ ionization or photoelectric type smoke detectors, and accordingly, the location of such devices for reliable early warning generally requires the installation of electrical conduits carrying the necessary wiring to a location which does not have an appropriate power outlet. In existing construction, the cost and inconvenience of installing such conduit, as well as the poor appearance of exposed conduit, in many instances results in a decision not to install a smoke detection and alarm system.
Other smoke detectors suitable for installation in homes and apartments employ local battery power supplies. These devices are satisfactory when the batteries are new. However, in almost all instances the batteries must be replaced or recharged periodically due to the fact that there is a constant electrical load on the batteries because the detector must be continuously energized. Additionally, with certain of these devices, power supply output adjustments must be made periodically to compensate for the declining output voltage of the battery supply. In some cases, human oversight may result in smoke detectors of the battery type being relatively ineffectual due to the fact that the necessary power supply adjustments or battery replacements are not made as required.
While the cost for most residential smoke detector and alarm systems is not prohibitive, some contractors and home owners will not have such systems installed even in new construction due to the added expense.